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A negative iodoform test (i.e., no yello...

A negative iodoform test (i.e., no yellow precipitate ) will be the result when NaOH + `I_2` is reacted with

A

`CH_3-CH_2-CH_2-oversetoversetH|C=O`

B

`H-oversetoverset(O)(||)C-CH_3`

C

`CH_3-undersetunderset(O)(||)C-CH_2-CH_3`

D

`CH_3-undersetunderset(OH)|C-CH_3`

Text Solution

AI Generated Solution

The correct Answer is:
To determine which compound will give a negative iodoform test when reacted with NaOH and I2, we need to understand the conditions that lead to a positive iodoform test. The iodoform test is positive for compounds that contain a methyl ketone (RCOCH3) or a secondary alcohol that can be oxidized to a methyl ketone. ### Step-by-Step Solution: 1. **Identify the Requirements for a Positive Iodoform Test:** - A positive iodoform test occurs with compounds that have a methyl group adjacent to a carbonyl group (methyl ketones) or secondary alcohols that can be oxidized to methyl ketones. 2. **Analyze the Given Options:** - We need to evaluate each option to see if it contains a methyl group next to a carbonyl group or is a secondary alcohol. 3. **Evaluate Each Option:** - **Option A:** CH3CH2CH2 (a straight-chain alkane with no functional groups) – This compound does not have a methyl group adjacent to a carbonyl group or any alcohol functionality. Thus, it will give a negative iodoform test. - **Option B:** Contains an alpha methyl group (e.g., CH3COCH3) – This will give a positive iodoform test. - **Option C:** Also contains an alpha methyl group (e.g., CH3CHOHCH3) – This will also give a positive iodoform test. - **Option D:** Contains an alpha methyl alcohol (e.g., CH3C(OH)CH3) – This will also give a positive iodoform test. 4. **Conclusion:** - Since only Option A (CH3CH2CH2) does not contain a methyl group adjacent to a carbonyl or is not a secondary alcohol, it will give a negative iodoform test. ### Final Answer: The correct option that will give a negative iodoform test is **Option A** (CH3CH2CH2).
To determine which compound will give a negative iodoform test when reacted with NaOH and I2, we need to understand the conditions that lead to a positive iodoform test. The iodoform test is positive for compounds that contain a methyl ketone (RCOCH3) or a secondary alcohol that can be oxidized to a methyl ketone. ### Step-by-Step Solution: 1. **Identify the Requirements for a Positive Iodoform Test:** - A positive iodoform test occurs with compounds that have a methyl group adjacent to a carbonyl group (methyl ketones) or secondary alcohols that can be oxidized to methyl ketones. 2. **Analyze the Given Options:** ...
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